Functional electrical stimulation (FES) uses an electrical pulse to force muscles to contract. ... Some companies claim that their devices support weight loss or build strong ab muscles without requiring exercise. However, there is no evidence that a muscle stimulator can substantially change a person's body.

Can you build muscle with electrical stimulation?

EMS (electrical muscle stimulation) is a machine that delivers a stimulating pulse to your muscles. ... Many athletes seeking a competitive advantage use EMS to build muscle faster. Since EMS can contract a muscle far longer than what an athlete could do themselves, it can grow more muscle and enhance training sessions.

What are the side effects of electrical stimulation?